The geometric sequence $(a_i)$ is defined by the formula: $a_i = -1 \left(\dfrac{4}{3}\right)^{i - 1}$ What is $a_{2}$, the second term in the sequence?
Solution: From the given formula, we can see that the first term of the sequence is $-1$ and the common ratio is $\dfrac{4}{3}$ The second term is simply the first term times the common ratio. Therefore, the second term is equal to $a_2 = -1 \cdot \dfrac{4}{3} = -\dfrac{4}{3}$.